Woodstock is very nice, if you are in the Towne Lake area, lots to do, work and live. Lawrenceville I find to be very spotty, some parts are very nice, some are downright scary. Gainesville...I personally wouldn't move there if someone paid me. IMHO.
Our criteria for moving was mainly school districts. 2 great sites to check them out are
Georgia Public Policy Foundation - www.gppf.org (georgia public policy foundation) it will list in pdf form how every school ranks. Also,
GreatSchools.net is a good resource too.
I just recently moved to Canton and I love it. We are renting for now. Publix is 2 minutes away and it is a great area. Ball Ground is further north and more of a small town feel. You get more for your money and it's becoming more popular every year. We are considering that too to buy a house in. We have friends in Kennesaw, and while it is very beautiful, good schools, lots to do, the traffic is just plain AWFUL.
Hope that helps. :-)